Digital broadcasting transmission/reception devices capable of improving a receiving performance and signal processing method thereof

ABSTRACT

Disclosed is a digital broadcasting transmission/reception system having an improved reception performance and in a signal-processing method thereof. A digital broadcasting transmitter comprises a TS stream generator for inputting robust and normal packets having stuff bytes in predetermined positions and generating dual TS stream by inserting the robust packets between the normal packets; a randomizer for randomizing the dual TS stream; a stuff byte exchanger for replacing the stuff bytes of a randomized data streams from the randomizer to a predetermined known data; and an encoder for encoding a data streams to which the known data is inserted. Accordingly, the present invention detects the known data from a signal received from a reception side and uses the detected known data for synchronization and equalization, so that the digital broadcasting reception performance can be improved at poor multipath channels.

This application is a divisional of prior application Ser. No.11/587,924, filed Oct. 26, 2006, in the U.S. Patent and TrademarkOffice, now pending, which claims priority from Korean PatentApplication No. 2004-33990, 2005-39309, and 2005-39317, filed on May 13,2004, May 11, 2005 and May 11, 2005, respectively, in the KoreanIntellectual Property Office, and International applicationPCT/KR05/01398, filed on May 12, 2005, the disclosure of which isincorporated herein in its entirety by reference.

TECHNICAL FIELD

The present invention relates to a digital broadcasting transmitter andreceiver, and more specifically, to a digital broadcasting transmitterfor replacing and transmitting stuff bytes inserted in data stream withpredefined known data in a dual stream to enhance reception performanceand a signal processing method thereof, and a corresponding digitalbroadcasting receiver and a signal processing method thereof.

BACKGROUND ART

The Advanced Television Systems Committee Vestigial Sideband (ATSC VSB),U.S-oriented terrestrial waves digital broadcasting system, is a singlecarrier scheme and uses field synchronizing signal by 312 segment unit.Accordingly, reception performance is not good in poor channels,especially in a doppler fading channel.

FIG. 1 is a block diagram showing a conventional transmitter of the ATSCVSB. The digital broadcasting transmitter of FIG. 1 forms and transmitsa dual stream by adding a robust data to a normal data of the existingATSC VSB system according to ‘ATSC Digital Television Standard (A/53B)’of Enhanced Vestigial Sideband (EVBS) system.

As shown in FIG. 1, the robust data in the digital broadcastingtransmitter is processed by a robust data processor (11), and the robustdata processor (11) has a Reed-Solomon (RS) encoder (11-1), a datainterleaver (11-2) and a packet formatter (11-3). The packet formatter(11-3) has a packet identifier (PID) inserter (not shown) and a ½ or ¼rate duplicator (not shown). Robust data processed by the robust dataprocessor (11) is multiplexed with a normal data by a multiplexer (MUX)(12).

The data output in the multiplexer (12) is randomized through arandomizer (13) and passes through an RS encoder (14) and an interleaver(15) in the form of a concatenated code to correct errors generated bythe channel. In addition, a symbol processor (16) performs enhancedcoding for the robust data, a deinterleaver (17) deinterleaves it beforereconstructing RS parity, and an RS parity deleting part (18) deletes RSparity to be compatible with the existing system. The data whose the RSparity is deleted is input to a VSB transmitter (19). The VSBtransmitter (19) includes an RS encoder (19-1), a data interleaver(19-2), a Trellis encoder (19-3) and a multiplexer (19-4) according tothe structure of a general VSB transmitter and performs RS encoding,data interleaving, 12 Trellis interleaved encoding, insertion of asynchronizing signal and a pilot, VSB modulation and up-convertor.

The above-mentioned conventional digital broadcasting transmittertransmits normal data and robust data in one channel as a dual streamscheme. The robust data is pre-processed by the robust data processor,in detail the pre-processing is performed by the RS encoder (11-1), theinterleaver (11-2) and the packet formatter (11-3) with the PID inserter(not shown) and the duplicator (not shown) so that the Moving PictureExperts Group-2 transport stream (MPEG-2 TS) is generated.

The robust data pre-processed by the robust data processor (11) ismultiplexed with the normal data by the multiplexer (MUX) (12) and israndomized by the randomizer (13) and the randomized data is outer-codedby the RS encoder (14) of an outer coder, and the outer-coded data isdispersed by the interleaver (15). In addition, the robust data isenhancedly coded by the symbol processor (16), and passes through thedeinterleaver (17) for performing symbol-to-byte conversion and datainterleaving for compatibility with the existing system and the paritydelete (18).

Later, as performed in the existing VSB transmitter, RS encoding, datainterleaving, 12 Trellis interleaved encoding, insertion of asynchronizing signal and a pilot, VSB modulation and so on are carriedout.

FIG. 2 shows a data format of the data output by the multiplexer (12).In FIG. 2, the normal data and the robust data are arranged at certainintervals so that the normal signal and the robust signal after Trellisencoding are distributed at regular intervals.

The U.S-oriented terrestrial waves digital television system of FIG. 1transmits in the dual stream by adding the robust data in the normaldata of the existing ATSC VSB system, so the existing normal data andthe robust data are transmitted altogether.

However, the U.S-oriented terrestrial waves digital television system ofFIG. 1 has a problem that in spite of dual stream transmission with therobust data, poor transmission performance at multipath channels ontransmitting the existing normal stream is not almost improved.

DISCLOSURE OF INVENTION Technical Problem

Therefore, an aspect of the present invention is to provide a digitalbroadcasting transmitter for replacing and transmitting stuff bytesinserted in dual stream with known data to enhance transmissionperformance and a signal processing method thereof and a correspondingdigital broadcasting receiver and a signal processing method thereof.

Technical Solution

To achieve an aspect of the present invention, a digital broadcastingtransmitter includes a robust data pre-processor for processing a robustdata to generate a robust data packet of a predetermined format; a TSstream generator for inputting a normal data packet, including stuffbytes in a certain location, and inserting the robust data packet atcertain intervals among the normal data packets so that a dual TS streamof a certain format is generated; a randomizer for randomizing the TSstream output from the TS stream generator; a stuff byte replacing partfor replacing the stuff bytes of the data output from the randomizerwith a predetermined known data; a first RS encoder for performing RSencoding of the data output from the stuff byte replacing part; aninterleaver for interleaving the data output from the first RS encoder;a symbol processor for coding the robust data among the data output fromthe interleaver; a first deinterleaver for deinterleaving the dataoutput from the symbol processor; and a Trellis encoder for initializingmemory at the beginning point of the known data among the data outputfrom the first interleaver and performing Trellis encoding.

Preferably, the known data has a predefined certain pattern.

Additionally, the digital broadcasting transmitter further includes asecond deinterleaver for deinterleaving the data output from the symbolprocessor; and a parity delete for deleting an RS parity in the dataoutput from the second deinterleaver.

Further, the digital broadcasting transmitter further includes a thirdRS encoder for performing RS encoding of the data output from the paritydelete; and a reinterleaver for interleaving the data output from thethird RS encoder.

More preferably, the digital broadcasting transmitter further includes aRS output buffer for inputting and temporarily storing the known datafrom the beginning point among the data output from the third RSencoder.

Further, the RS output buffer inputs and stores the known data alteredaccording to initializing of memory from the Trellis encoder.

Additionally, the digital broadcasting transmitter further includes aparity restructuring part for generating the altered parity by inputtingthe altered known data from the RS output buffer and performing RSencoding, and outputting the altered parity to the Trellis encoder so asto replace the parity added by the third RS encoder.

Further, the stuff bytes are inserted in an adaptation field of thenormal data packet.

Additionally, the normal data packet includes information on length ofthe inserted stuff bytes at a certain location.

Meanwhile, a method for signal processing for a digital broadcastingtransmitter according to the present invention includes a robust datapreprocessing step of processing the robust data to generate a robustdata packet of a certain format; a TS stream generating step of beinginput with a normal data packet where stuff bytes are inserted at acertain location and inserting the robust data packet at certainintervals in the normal data packet to generate a dual TS stream of apredetermined format; a randomizing step of randomizing the TS streamgenerated in the TS stream generating step; a stuff byte replacing stepof replacing the stuff bytes in the data output from the randomizingstep with a predetermined known data; a first RS encoding step ofperforming RS encoding of the data output from the stuff byte replacingstep; an interleaving step of interleaving the data output from thefirst RS encoding step; a symbol processing step of coding the robustdata of the data output from the interleaving step; a firstdeinterleaving step of deinterleaving the data output from the symbolprocessing step; and a Trellis encoding step of initializing memory atthe beginning point of the known data of the data output from the firstdeinterleaving step and performing Trellis encoding.

Additionally, A digital broadcasting transmitter according to anotherembodiment includes a TS stream generator for receiving a normal datapacket and a robust data packet respectively having stuff bytes at acertain location and inserting the robust data packet at certainintervals among the normal data packet to generate dual TS stream of acertain format; a randomizer for randomizing the TS stream output fromthe TS stream generator; a stuff byte replacing part for replacing thestuff bytes of the data output in the randomizer with a predeterminedknown data; a first RS encoder for performing RS encoding of the dataoutput from the stuff byte replacing part; an interleaver forinterleaving the data output in the first RS encoder; a symbol processorfor performing coding of the robust data of the data output in theinterleaver; a first deinterleaver for deinterleaving the data output inthe symbol processor; and a Trellis encoder for initializing memory ofthe known data of the data output in the deinterleaver at the beginningpoint, and performing Trellis encoding.

Preferably, the stuff bytes are inserted in adaptation field of thenormal data packet and the robust data packet.

Further, the normal data packet and the robust data packet includeinformation on length of the inserted stuff bytes at a certain location.

Additionally, a method for signal processing for a digital broadcastingtransmitter includes a TS stream generating step of receiving normaldata packet and robust data packet respectively having stuff bytes at acertain location and inserting the robust data packet among the normaldata packet at certain intervals to generate dual TS stream of a certainformat; a randomizing step of randomizing the TS stream generated in theTS stream generating step; a stuff byte replacing step of replacing thestuff bytes of data output in the randomizing step with a predeterminedknown data; a first RS encoding step of performing the RS encoding ofdata output in the stuff byte replacing step; an interleaving step ofinterleaving data output in the first RS encoding step; a symbolprocessing step of performing coding the robust data of data output inthe interleaving step; a first deinterleaving step of deinterleavingdata output in the symbol processing step; and a Trellis encoding stepof initializing memory of the known data of data output in the firstdeinterleaving step at the beginning point and performing Trellisencoding.

Meanwhile, a digital broadcasting receiver according to the presentinvention includes a demodulator for receiving and demodulating signalencoded by inserting a predetermined known data in a certain location ofdual stream, where stuff bytes are inserted in the certain location,from the digital broadcasting receiver; a known data output part fordetecting a location of the known data from the demodulated signal andoutputting the known data; an equalizer for equalizing the demodulatedsignal; a Viterbi decoder for correcting errors of the equalized signaland decoding using the detected known data; a deinterleaver fordeinterleaving data output in the Viterbi decoder; a derandomizer forderandomizing data output in the deinterleaver; a de-multiplexer forseparating robust data and normal data in data output in thederandomizer; and a robust data processor for processing andrestructuring the robust data.

Preferably, the known data output part includes a known symbol detectorfor detecting information on the certain location where the known datais inserted in received signal; a segment flag generator for generatingdata frame including one or more segment indicating the location with apredetermined identification flag; a Trellis interleaver for encodingthe data frame as encoding in the digital broadcasting transmitter; anda known data extractor for inserting and outputting the known data atthe location where the identification flag is indicated in theinterleaved data frame.

Further, the known data output part outputs the detected known data tothe demodulator, and the demodulator performs demodulation using theknown data.

Additionally, a method for signal processing for a digital broadcastingreceiver according to the present invention includes a demodulating stepof receiving and demodulating encoded signal by inserting apredetermined known data in a certain location of dual stream, wherestuff bytes are inserted in the certain location, from a digitalbroadcasting transmitter; a known data outputting step of detecting alocation of the known data from the demodulated signal and outputtingthe known data; a equalizing step of equalizing the demodulated signal;a decoding step of correcting errors of the modulated signal using thedetected known data and decoding; a deinterleaving step ofdeinterleaving data output in the decoding step; a derandomizing step ofderandomizing data output in the deinterleaving step; a demultiplexingstep of separating robust data and normal data from data output in thederandomizing step; and a robust data processing step of processing andrestructuring the robust data.

Advantageous Effects

According to the present invention, a digital broadcasting transmittergenerates and inserts stuff bytes in a MPEG-2 TS packet, the insertedstuff bytes are replaced with known data and transmitted to a digitalbroadcasting receiver, and a digital broadcasting receiver detects anduses the known data. Accordingly, there are effects of compatibilitywith the existing digital broadcasting system, lower complexity ofhardware, and enhanced digital broadcasting reception performance inpoor multipath channels.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a transmitter of a conventionalU.S-oriented terrestrial waves digital broadcasting (ATSC VSB) system,

FIG. 2 is a view showing a format of ATSC VSB data,

FIG. 3 is a view showing a frame structure of a TS packet,

FIG. 4 is a view showing a frame structure of a TS packet includingstuff bytes according to the present invention,

FIG. 5 is a block diagram of a digital broadcasting transmitteraccording to the present invention,

FIG. 6 and FIG. 7 are views showing a format of data output from arandomizer of FIG. 5,

FIG. 8 and FIG. 9 are views showing a format of data output from aninterleaver of FIG. 5,

FIG. 10 and FIG. 11 are views showing a format of data output from aTrellis encoder of FIG. 5,

FIG. 12 and FIG. 13 are views showing a format of data which parity isrestructured according to Trellis initialization of FIG. 5,

FIG. 14 is a block diagram of a digital broadcasting transmitteraccording to the present invention, and

FIG. 15 is a view provided to describe a known data output part of FIG.10.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail withreference to the accompanying drawings.

FIG. 5 is a block diagram of a digital broadcasting transmitteraccording to the present invention. The digital broadcasting transmitterof FIG. 5 has the structure to improve the EVSB system that LG(Zenith)/ATI proposed. In detail, stuff bytes are added in a MPEG-2packet of normal data, the added stuff bytes are replaced with knowndata in the digital broadcasting transmitter, and then are transmitted.Then, the known data is detected in a corresponding digital broadcastingreceiver and is used to compensate distortion by a channel.

In FIG. 5, the digital broadcasting transmitter has a first multiplexer(110) for multiplexing normal data and robust data output from a robustdata pre-processor (100), a randomizer (120) for randomizing themultiplexed data, a stuff byte replacing part (130) for replacing thestuff bytes, inserted in the normal data or robust data of therandomized data, with a particular sequence, a first RS encoder (140)for constructing the data output from the stuff byte replacing part(130) in the form of concatenated code to correct errors by a channel, afirst interleaver (150) for interleaving data, a symbol processor (150)a symbol processor (160) for enhancedly coding the robust data in theinterleaved data, a control signal generator (170), de-interleaver (180)for de-interleaving the enhancedly coded data to be comparable with theexisting system and a RS parity deleting part (190) for deleting an RSparity. The digital broadcasting transmitter employs the EVSB system andis constructed to be compatible with the existing system.

In addition, the digital broadcasting transmitter of FIG. 5 has a thirdRS encoder (210) for carrying out a VSB transmitting channel coding, areinterleaver (220) for interleaving data again, and a Trellis encoder(230) for performing ⅔ rate Trellis encoding. The Trellis encoder (230)carries out the process to initialize the stuff bytes.

The robust data pre-processor (100) has a second RS encoder (101) forperforming RS-encoding of a robust stream, a second interleaver (103)for interleaving the RS-encoded robust stream, and a packet formatter(305) for formatting the interleaved robust stream in a certain format.

That is, the robust data pre-processor (100) inserts PID in theRS-encoded robust stream through the packet formatter (305) and doublyduplicates it. Then, the robust data pre-processor (100) outputs robustMPEG packets as formatted to insert among the normal MPEG packets atcertain intervals.

Meanwhile, the normal data packets or robust data packets to be input tothe first multiplexer (110) according to the present invention includethe stuff bytes. FIG. 3 is a view showing a frame structure of a generalTS stream packet. FIG. 4 is a view showing a frame structure of a MPEG-2TS stream packet including adaptation field with stuff bytes accordingto the present invention.

In FIG. 4, a MPEG-2 packet of 188 bytes consists of information signal(MPEG-2 header) of 4 bytes including MPEG synchronizing signal,adaptation field length information of 1 byte, other information of 1byte, adaptation field data with stuff bytes of n bytes, and ES data of‘188−(4+2+n)’ bytes.

As shown in FIG. 3, a general TS stream packet frame consists of theMPEG-2 header and the adaptation field or the ES data. The normal datapacket or robust data packet according to the present invention, asshown in FIG. 4, has structure that stuff bytes are inserted in theadaptation field so that TS stream includes the adaptation field. SuchMPEG-2 TS packet of the normal data or robust data is input to the firstmultiplexer (110).

The first multiplexer (110) multiplexes the above-mentioned normal dataor robust data output from the robust data pre-processor (100), and therandomizer (120) randomizes the multiplexed data.

The stuff byte replacing part (130) replaces stuff bytes, inserted inthe normal data or robust data of the randomized data, with, forexample, a particular sequence generated by a particular sequencegenerator (not shown) to output them. The particular sequence is datahaving predefined pattern that the transmitter and the receiver havealready known each other, which is hereinafter referred to as knowndata.

FIG. 6 shows a data format after replacing stuff bytes of n bytes in anormal data packet with the particular sequence data in outputting fromthe randomizer (120). In FIG. 6, normal data packets and robust datapackets are arranged at certain intervals and known data instead ofstuff bytes are inserted in the adaptation fields of the normal datapackets.

Further, FIG. 7, when stuff bytes are inserted in normal data packetsand robust data packets, respectively, to be input to the randomizer(120), shows a data format after replacing stuff bytes of n bytes innormal data packets and robust data packets with the particular sequencedata in outputting from the randomizer (120). In FIG. 7, normal datapackets and robust data packets are arranged at certain intervals andknown data instead of stuff bytes are inserted in the adaptation fieldsof the normal data packets and robust data packets.

In addition, as described above, the header of MPEG-2 packet data outputfrom the randomizer (120) includes the first byte of a synchronizingsignal and 3 bytes of packet identity (PID). The first 2 bytes ofadaptation field of certain bytes include adaptation field lengthinformation. In other words, the first 2 bytes of the adaptation fieldhave information on length of stuff bytes inserted in the adaptationfield, that is, length of known data. As the beginning location of theknown data in a packet is fixed, the receiver can know the informationon location and length, that is, quantity of the known data according tothe information inserted in the first 2 bytes of the adaptation field.

The first RS encoder (140) encodes the data output from the stuff bytereplacing part (130), and performs outer coding in the form ofconcatenated code to correct errors generated by a channel.

The first interleaver (150) interleaves the data output from the firstRS encoder (140). The symbol processor (160) performs enhanced coding ofthe robust data in the interleaved data. To be compatible with theexisting system, the de-interleaver (180) deinterleaves and the RSparity deleting part (190) deletes parity in enhanced-coded data.

FIG. 8 and FIG. 9 show a data format after interleaving data by thefirst interleaver (150). MPEG-2 packets of FIG. 6 and FIG. 7 aredispersed in 52 units by the first interleaver (150), as those in FIG. 8and FIG. 9. Data with the same byte location in MPEG-2 packet constructthe same column, as shown FIG. 8 after interleaving. In addition, thedata format output from the Trellis encoder (230) after 12 symbolinterleaving is shown in FIG. 10 and FIG. 11. That is, data located inthe same byte of MPEG-2 packets construct almost one data segment, asshown in FIG. 10 and FIG. 11, after Trellis encoding. Therefore, ifstuff bytes are consecutively added in certain location of MPEG-2 packetand randomized, and the stuff bytes are replaced with a particularsequence, with Trellis encoding, the stuff bytes inserted in the samebyte location form one data segment, which is detected and used in thedigital broadcasting receiver as the known data to improve receptionperformance.

The control signal generator (170) detects information on the adaptationfield length, and generates and outputs flag signal indicating alocation of stuff bytes or known symbol sequence data.

Furthermore, to perform a VSB transmitting channel coding, the third RSencoder (210) performs RS encoding, the reinterleaver (220) interleavesdata again, and the Trellis encoder (230) performs ⅔ rate Trellisencoding.

An RS output buffer (240) and a parity restructuring part (250)restructure parity of the known data which is altered according to theinitialization of the Trellis encoder (230) and perform the VSBtransmitting channel coding with the Trellis encoder (230).

The RS output buffer (240) outputs the known data from the data withoutRS parity which is output from the RS parity deleting part (190) fromthe beginning, and temporarily stores the output known data. Then, whenthe known data is Trellis-encoded in the Trellis encoder (230) accordingto the initialization, the RS output buffer (240) receives the knowndata altered according to the initialization from the Trellis encoder(230), replaces the previously buffered known data with it and storesthe altered known data, and inputs the altered known data to the parityrestructuring part (250) to regenerate parity.

The parity restructuring part (250) receives the known data alteredaccording to the initialization, regenerates parity according to thealtered data, and inputs it to the trellis encoder (230) so that theprevious parity is replaced with the new parity.

The Trellis encoder (230) converts the data output from thereinterleaver (220) into symbol and performs symbol mapping through ⅔rate Trellis encoding. Furthermore, as above-mentioned, the Trellisencoder (230) performs 12 Trellis encoder initialization at beginninglocation of the known data, that is, known symbol sequence so that valueof memory element of the encoder becomes a particular value, forexample, ‘00’. The Trellis encoder (230) initializes a value temporarilystored in memory element itself at beginning location of the known dataand carries out Trellis encoding of the known data.

Therefore, the data packet output from the Trellis encoder (230) to amultiplexer (260) includes the known data altered according to thememory element initialization of the Trellis encoder (230), and has dataformat added with parity according to RS encoding of the altered knowndata.

FIG. 10 and FIG. 11 show data formats output from the Trellis encoder(230), which are processed with 12 symbol interleaving. One fieldincludes six convolutional interleavers so that six sequences includingstuff bytes appear. In other words, if TS stream has stuff bytes of 10bytes, known symbol sequences of ‘0*6=60’ are generated in one field.

FIG. 12 and FIG. 13 show a data format after RS re-encoding and parityrestructuring by the parity restructuring part (250) of FIG. 5. That is,if the Trellis encoder (230) is initialized at beginning point ofsequence of known symbol, the parity restructuring part (250) altersoutput parity of the third RS encoder (210) according to the value ofinitialization and the altered parity is input to the Trellis encoder(230). Accordingly, the Trellis encoder (230) updates the altered parityand carries out the Trellis encoding so that there will be no problemwhen an RS decoder of the digital broadcasting receiver decodes.

In other words, initialization of the Trellis encoder (230) is performedin order for Trellis encoded data to form particular sequence duringknown symbol sequence section. Then, in order to alter RS paritycorresponding to known symbol sequence altered according to theinitialization, RS encoding of the altered known symbol sequence isperformed again so that parity is altered. The existing parity isreplaced with the altered parity so that the data format like FIG. 12and FIG. 13 is generated.

To the data which is encoded via the Trellis encoder (230), the RSoutput buffer (240) and the parity restructuring part (250), and mappedinto symbol, field sync signal and segment sync signal are inserted bythe second multiplexer (260) like the data format of FIG. 2. DC offsetis added in a transmitter end to generate pilot so that VSB modulationis performed, and the data is converted into RF and transmitted.

FIG. 14 is a block diagram of a digital broadcasting receivercorresponding to the digital broadcasting transmitter of FIG. 5according to the present invention. If the received signal includesnormal robust and stuff bytes, the digital broadcasting receiver haselements for decoding.

The digital broadcasting receiver of FIG. 14 includes a demodulator(510) for lowering RF signal to baseband and demodulating it, anequalizer (520) for deleting inter-symbol interference, a Viterbidecoder or Trellis decoder (530), a deinterleaver (540), an RS encoder(550), an derandomizer (560), a demultiplexer (570) for separatingnormal data and robust data, a control signal generator (580) forgenerating control signal to control dual stream, a robust dataprocessor (590), and a known data output part (600) for detectinglocation of stuff bytes and outputting known data.

The Viterbi decoder (530), the deinterleaver (540), the RS encoder(550), and the inverse randomizer (560) correct error from the equalizedsignal and perform decoding.

The demodulator (510) converts RF signal received via channel intobaseband signal through tuner/IF (not shown), detects sync of theconverted baseband signal and performs demodulation. The equalizer (520)compensates multipath channel distortion of the demodulated signal.

Meanwhile, the known data output part (600) detects information on stuffbyte length inserted in the reserved part of field sync data segmentsection or the first 2 bytes of adaptation field to acquire locationinformation on known symbol, and outputs known data from the acquiredinformation on location.

FIG. 15 shows the known data output part (600) for detecting the knowndata in the digital broadcasting receiver.

The known data output part (600) includes a known symbol detector (610),a segment flag generator (620), a Trellis interleaver (630), and a knowndata extractor (640).

If the information on the quantity (the number) of stuff bytes isinserted in control information bit, including information on adaptationfield length of data header, or in the reserved part of field sync datasegment section, the known symbol detector (610) of the known dataoutput part (600) of the digital broadcasting receiver detects theinformation on the quantity of known data. According to the detectedinformation, the segment flag generator (620) and the Trellisinterleaver (630) acquire information on the location and the number ofknown symbol. From the acquired information on the location and thenumber of known, the known data extractor (640) outputs the known dataso that receiving performance of the digital broadcasting receiver isimproved. As the location of stuff bytes is fixed all the time, ifquantity of stuff bytes is detected, the segment flag generator (620)and the Trellis interleaver (630) can be implemented using a counter anda control logic.

That is, the known symbol detector (610) extracts information of knowndata location from control information bit including information onadaptation field length of the demodulated data header. The informationon known data location includes the information on known data length. Asthe known data location is preset, the location and number of knownsymbols according to encoding of known data can be acquired by knowingthe length.

According to the location and number of the known symbol, the segmentflag generator (620) marks a predetermined flag of length correspondingto the number at the corresponding location and generates at least onesegment and a MPEG-2 transmission frame including the segment.

The Trellis interleaver (630) encodes transmission frame generated inthe segment flag generator (620) like interleaving in the digitalbroadcasting transmitter.

The known data extractor (640) inserts predefined known data at thelocation for known symbol which is identified by the flag intransmission frame encoded and output from the Trellis interleaver(630), and outputs the known data-inserted frame.

Meanwhile, errors of signal equalized by the equalizer (520) arecorrected through the Viterbi decoder (530) and the signal is decoded tosymbol data. The deinterleaver (540) rearranges data dispersed by thefirst interleaver (150) of the transmitter in FIG. 5. Errors of thedeinterleaved data are corrected through the RS encoder (550). Thecontrol signal generator (580) generates control signal to processnormal data and robust data. The corrected data through the RS encoder(550) is derandomized through the derandomizer (560). The derandomizeddata separates into normal data and robust data through thedemultiplexer (570) and the robust data is processed by the robust dataprocessor (590).

As above described, stuff bytes are generated and inserted in MPEG-2 TSpacket, the inserted stuff bytes are replaced with known data andtransmitted from the digital broadcasting transmitter, and then thedigital broadcasting receiver detects and use the known data.Accordingly, receiving performance of the digital broadcasting receiversuch as sync acquiring and equalizing performance can be improved.

The invention claimed is:
 1. A digital broadcasting receiver,comprising: a receiver to receive a data stream including a field sync,a segment sync, known data, information regarding supplementary data;and a processor to process the data stream using the known data, whereinthe supplementary data is Reed-Solomon (RS) encoded, interleaved andpacket formatted before the data stream is received at the digitalbroadcasting receiver, and wherein, before the data stream is receivedat the digital broadcasting receiver, the data stream is Trellis encodedusing internal memories of a Trellis encoder, and the internal memoriesare reset at a predetermined time point when the known data is input tothe Trellis encoder.
 2. The digital broadcasting receiver as claimed inclaim 1, wherein the known data are included in a predetermined locationof the data stream according to a control signal to control an insertionprocess of the known data.
 3. The digital broadcasting receiver asclaimed in claim 1, wherein an RS parity of the data stream iscompensated to correspond to the resetting of the internal memories byan RS encoder before the data stream is received at the receiver.
 4. Thedigital broadcasting receiver as claimed in claim 1, wherein the datastream further comprises information regarding a length of the knowndata.
 5. The digital broadcasting receiver as claimed in claim 1,wherein the operation of formatting a packet is an operation ofinserting packet identification (PID) into the supplementary data usinga packet formatter comprised in the digital broadcasting transmitter. 6.The digital broadcasting receiver as claimed in claim 1, wherein theoperation of formatting a packet is an operation of duplicating thesupplementary data using a packet formatter comprised in the digitalbroadcasting transmitter.
 7. The digital broadcasting receiver asclaimed in claim 1, wherein the supplementary data are inserted betweennormal packets, each of which contains normal data, using a packetformatter before the data stream is received at the receiver.
 8. Thedigital broadcasting receiver as claimed in claim 1, wherein thesupplementary data is RS encoded, interleaved, and packet formatted, andis multiplexed to the data stream before the data stream is received atthe receiver.
 9. The digital broadcasting receiver as claimed in claim1, further comprising: a demodulator for demodulating the received datastream; and a known data detector for detecting the known data from thedata stream, wherein the processor comprises: a de-multiplexer forseparating the data stream into normal data and the supplementary data;and a robust data processor for processing the separated supplementarydata.
 10. A method for processing a stream of a digital broadcastingreceiver, the method comprising: receiving a data stream including afield sync, a segment sync, known data, information regardingsupplementary data; and processing the data stream using the known data,wherein the supplementary data is Reed-Solomon (RS) encoded, interleavedand packet formatted before the data stream is received at the digitalbroadcasting receiver, wherein, before the data stream is received forthe processing, the data stream is Trellis encoded using internalmemories of a Trellis encoder, and the internal memories are reset at apredetermined time point when the known data is input to the Trellisencoder.
 11. The method as claimed in claim 10, wherein the known dataare included in a predetermined position of the data stream according toa control signal to control the known data to be inserted.
 12. Themethod as claimed in claim 10, wherein an RS parity of the data streamis compensated to correspond to the resetting of the internal memoriesby an RS encoder before the data stream is received at the receiver. 13.The method as claimed in claim 10, wherein the data stream furthercomprises information regarding a length of the known data.
 14. Themethod as claimed in claim 10, wherein the operation of formatting apacket is an operation of inserting packet identification (PID) into thesupplementary data using a packet formatter comprised in the digitalbroadcasting transmitter.
 15. The method as claimed in claim 10, whereinthe operation of formatting a packet is an operation of duplicating thesupplementary data using a packet formatter comprised in the digitalbroadcasting transmitter.
 16. The method as claimed in claim 10, whereinthe supplementary data are inserted between normal packets, each ofwhich contains normal data, using a packet formatter before the datastream is received at the receiver.
 17. The method as claimed in claim10, wherein the supplementary data is RS encoded, interleaved, andpacket formatted, and is multiplexed to the data stream before the datastream is received at the receiver.
 18. The method as claimed in claim10, further comprising: detecting the known data from the data stream;and demodulating the received data stream, wherein the processingcomprises: de-multiplexing in a manner of separating the data streaminto normal data and the supplementary data; and robust data processingthe separated supplementary data.